Cyclic polyolefins derived from hexyne, octyne, nonyne, pentadecyne and their copolymers with acetylene

ABSTRACT

Disclosed are saturated cyclic monopolymers derived from hexyne, octyne, nonyne, pentadecyne and saturated cyclic copolymers derived from acetylene and a second alkyne monomer that is hexyne, octyne, nonyne, or pentadecyne.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application makes reference to the following patent applicationsand patents: International Patent Application No. PCT/US2015/034888,entitled “Metallacycloalkylene Complexes and Use for AlkynePolymerization to Cyclic Polyacetylenes,” filed Jun. 9, 2015; which is acontinuation-in-part of U.S. patent application Ser. No. 14/299,449,entitled “Tridentate Pincer Ligand Supported Metal-Alkylidyne andMetallacycloalkylene Complexes for Alkyne Polymerization,” filed Jun. 9,2014, now U.S. Pat. No. 9,206,266, issued Dec. 8, 2015, which claimspriority from U.S. Provisional Patent Application No. 61/845,764, filedJul. 12, 2013, and is a continuation-in-part of PCT/US2012/065841, filedNov. 19, 2012, which claims priority from U.S. Provisional PatentApplication No. 61/567,909, filed Dec. 7, 2011.

U.S. patent application Ser. No. 15/286,780, entitled “ONO PincerLigands and ONO Pincer Ligand Comprising Metal Complexes,” filed Oct. 6,2016, which is a division of U.S. patent application Ser. No.14/077,822, filed Nov. 12, 2013, now U.S. Pat. No. 9,464,104, issuedOct. 11, 2016, which is a continuation in part of PCT/US2012/037302,filed May 10, 2012, which claims priority from Provisional PatentApplication No. 61/484,793, filed May 11, 2011.

U.S. patent application Ser. No. 13/872,544, entitled “Method forLinking Two or More Metals for Photo and Electronic Materials,” filedApr. 29, 2013, now U.S. Pat. No. 8,889,879, issued Nov. 18, 2014, whichis a continuation in part of PCT/US2011/057851, filed Oct. 26, 2011,which claims priority from Provisional Patent Application No.61/407,248, filed Oct. 27, 2010. U.S. patent application Ser. No.13/852,611, entitled “NCN Trianionic Pincer Complexes as Catalysts forOlefin Polymerization and Isomerization,” filed Mar. 28, 2013, now U.S.Pat. No. 9,637,425, issued Oct. 31, 2013, which is a continuation inpart of PCT/US2011/052532, filed Sep. 21, 2011, that claims priorityfrom U.S. Provisional Patent Application No. 61/387,288, filed Sep. 28,2010.

U.S. patent application Ser. No. 13/254,510, entitled “Trianionic PincerLigands, a CR(III)/CR(V) Catalytic System and Its Use for CatalyticAerobic Oxidation of Organic Substrates,” filed Sep. 2, 2011, now U.S.Pat. No. 8,846,950, issued Sep. 30, 2014, which is a continuation inpart of PCT/US2010/26034, filed Mar. 3, 2010, which claims priority fromProvisional Patent Application No. 61/156,946, filed Mar. 3, 2009.

U.S. patent application Ser. No. 12/437,845, entitled “Method forTransferring N-Atoms from Metal Complexes to Organic and InorganicSubstrates,” filed May 8, 2009, now U.S. Pat. No. 8,063,236, issued Nov.22, 2011, which claims priority from U.S. Provisional Patent ApplicationNo. 61/051,599, filed May 8, 2008.

U.S. patent application Ser. No. 13/790,720, entitled “CatalystsContaining N-Heterocyclic Carbenes for Enantioselective Synthesis,”filed Mar. 8, 2013, now U.S. Pat. No. 8,691,998, issued Apr. 8, 2014,which is a division of U.S. patent application Ser. No. 12/527,635,filed Jan. 20, 2010, now U.S. Pat. No. 8,455,661, issued Jun. 4, 2013,which is a continuation in part of PCT/US2008/054137, filed Feb. 15,2008, which claims priority from U.S. Provisional Patent Application No.60/985,205, filed Nov. 3, 2007 and U.S. Provisional Patent ApplicationNo. 60/890,484, filed Feb. 18, 2007.

U.S. Provisional Patent Application No. 62/561,941, entitled“Macrocyclic Poly(Alkane)S And Poly(Alkane-Co-Alkene)S,” filed Sep. 22,2017.

The entire contents and disclosures of these patent applications andpatents are incorporated herein by reference.

STATEMENT OF JOINT RESEARCH AGREEMENT

In compliance with 37 C.F.R. § 1.71 (g)(1), disclosure is herein madethat the inventions described and claimed herein were made pursuant to aJoint Research Agreement (LAW-2015-0682) as defined in 35 U.S.C. 103(c)(3), that was in effect on or before the date the inventions weremade, and as a result of activities undertaken within the scope of theJoint Research Agreement, by or on the behalf of ExxonMobil ChemicalCompany, a division of Exxon Mobil Corporation, and the University ofFlorida.

BACKGROUND Field of the Invention

The disclosed invention relates generally to cyclic polymers.

Related Art

Cyclic polymers have dramatically different physical properties comparedwith those of their equivalent linear counterparts. However, theexploration of cyclic polymers is limited because of the inherentchallenges associated with their synthesis. Conjugated linearpolyacetylenes are important materials for electrical conductivity,paramagnetic susceptibility, optical nonlinearity, photocondudivity, gaspermeability, liquid crystallinity and chain helicity. However, theircyclic analogues are unknown, and therefore the ability to examine how acyclic topology influences their properties is currently not possible.There is a need to rapidly polymerize alkynes to form conjugatedmacrocycles in high yield.

SUMMARY

According to first broad aspect, the disclosed invention provides acomposition comprising a saturated cyclic copolymer having a structuralformula:

wherein: R is n-butyl, n-hexyl, n-heptyl, or n-tetradecyl; n and m eachhas various values, with a ratio of n/m<1.

According to a second broad aspect, the disclosed invention provides acomposition comprising a saturated cyclic homopolymer having astructural formula:

wherein: R is n-butyl, n-hexyl, n-heptyl, n-tetradecyl; n≥1.

According to a third broad aspect, the disclosed invention provides amethod of preparing a saturated cyclic polymer. The method compriseshydrogenating an unsaturated cyclic polymer using a hydrogenationcatalyst to produce a saturated cyclic polymer. The saturated cyclicpolymer comprises a saturated cyclic homopolymer or a saturated cycliccopolymer. The saturated cyclic homopolymer has a structural formula:

wherein: R is n-butyl, n-hexyl, n-heptyl, or n-tetradecyl; n≥1. Thesaturated cyclic copolymer has a structural formula:

wherein: R is n-butyl, n-hexyl, n-heptyl, n-tetradecane; n and m eachhas various values, with a ratio of n/m<1.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theinvention, and, together with the general description given above andthe detailed description given below, serve to explain the features ofthe invention.

FIG. 1 illustrates the synthesis of a catalyst (complex 4), according toan embodiment of the disclosed invention.

FIG. 2 is a molecular structure of complex 4, according to an embodimentof the disclosed invention.

FIG. 3 shows a scheme for synthesis of a saturated cyclic polymer,according to an embodiment of the disclosed invention.

FIG. 4 shows a scheme for synthesis of a saturated cyclic homopolymer of1-hexyne, 1-octyne, 1-nonyne, or 1-pentadecyne, according to anembodiment of the disclosed invention.

FIG. 5 shows a scheme for synthesis of a saturated cyclic copolymer of1-hexyne, 1-octyne, 1-nonyne, or 1-pentadecyne with acetylene, accordingto an embodiment of the disclosed invention.

FIG. 6 is an exemplary ¹H NMR spectrum of Hex-1-H in CDCl₃ at 25° C.,according to an embodiment of the disclosed invention.

FIG. 7 is an exemplary ¹H NMR spectrum of poly oct-1 in C6D6 at 25° C.,according to an embodiment of the disclosed invention.

FIG. 8 is an exemplary ¹H NMR spectrum of non-1 (bottom) and non-1-H(top) in CDCl₃ at 25° C., according to an embodiment of the disclosedinvention.

FIG. 9 is an exemplary ¹H NMR spectrum of Ptd-1 (bottom) and Ptd-1-H(top) in CDCl₃ at 25° C., according to an embodiment of the disclosedinvention.

FIG. 10 is an exemplary ¹H NMR spectrum of Ac-Hex-H-1 in CDCl₃ at 25°C., according to an embodiment of the disclosed invention.

FIG. 11 is an exemplary ¹H NMR spectrum of Ac-Non-H-1 in CDCl3 at 25°C., according to an embodiment of the disclosed invention.

FIG. 12 is an exemplary ¹H NMR spectrum of Ac-Non-H-2 in C6D6 at 25° C.,according to an embodiment of the disclosed invention.

FIG. 13 is an exemplary ¹H NMR spectrum of Ac-Ptd-H-1 in CDCl3 at 25°C., according to an embodiment of the disclosed invention.

FIG. 14. is a picture of exemplary saturated cyclic polymers, accordingto an embodiment of the disclosed invention.

DETAILED DESCRIPTION OF THE INVENTION Definitions

Where the definition of terms departs from the commonly used meaning ofthe term, applicant intends to utilize the definitions provided below,unless specifically indicated.

It is to be understood that the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive of any subject matter claimed. In this application,the use of the singular includes the plural unless specifically statedotherwise. It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. In thisapplication, the use of “or” means “and/or” unless stated otherwise.Furthermore, use of the term “including” as well as other forms, such as“include”, “includes,” and “included,” is not limiting.

For purposes of the disclosed invention, the term “comprising”, the term“having”, the term “including,” and variations of these words areintended to be open-ended and mean that there may be additional elementsother than the listed elements.

For purposes of the disclosed invention, directional terms such as“top,” “bottom,” “upper,” “lower,” “above,” “below,” “left,” “right,”“horizontal,” “vertical,” “up,” “down,” etc., are used merely forconvenience in describing the various embodiments of the disclosedinvention. The embodiments of the disclosed invention may be oriented invarious ways. For example, the diagrams, apparatuses, etc., shown in thedrawing figures may be flipped over, rotated by 90° in any direction,reversed, etc.

For purposes of the disclosed invention, a value or property is “based”on a particular value, property, the satisfaction of a condition, orother factor, if that value is derived by performing a mathematicalcalculation or logical decision using that value, property or otherfactor.

For purposes of the disclosed invention, it should be noted that toprovide a more concise description, some of the quantitative expressionsgiven herein are not qualified with the term “about.” It is understoodthat whether the term “about” is used explicitly or not, every quantitygiven herein is meant to refer to the actual given value, and it is alsomeant to refer to the approximation to such given value that wouldreasonably be inferred based on the ordinary skill in the art, includingapproximations due to the experimental and/or measurement conditions forsuch given value.

For purposes of the disclosed invention, the term “analogue” and theterm “analog” refer to one of a group of chemical compounds that sharestructural and/or functional similarities but are different in respectto elemental composition. A structural analog is a compound having astructure similar to that of another one, but differing from it inrespect of one or more components, such as one or more atoms, functionalgroups, or substructures, etc. Functional analogs are compounds that hassimilar physical, chemical, biochemical, or pharmacological properties.Functional analogs are not necessarily also structural analogs with asimilar chemical structure.

For purposes of the disclosed invention, the term “room temperature”refers to a temperature of from about 20° C. to about 25° C.

Description

While the invention is susceptible to various modifications andalternative forms, specific embodiment thereof has been shown by way ofexample in the drawings and will be described in detail below. It shouldbe understood, however that it is not intended to limit the invention tothe particular forms disclosed, but on the contrary, the invention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and the scope of the invention.

Cyclic polymers do not contain end groups,¹ and as a result demonstratea number of unique physical properties.² For example, the density³,refractive index^(4,5), glass-transition temperature,⁶ viscoelasticity,⁷reptation⁸ and surface properties⁹ of cyclic polymers all differ fromthose of their more common linear analogues. Most of the seminal workthat compares linear versus cyclic polymers relies on theory or onexperimental work involving a limited set of macrocycles, for examplepoly(dimethylsiloxane).¹⁰ Despite research in this area for over half acentury there still remains a lack of knowledge regarding the propertiesand fundamental behavior of cyclic analogues of important commercialpolymers, primarily because of their difficult syntheses andpurification.

Ring closing^(11,12) of large chains is one method of creating cyclicpolymers, but requires dilute conditions to be efficient, and thusprecludes large-scale synthesis. Competing intermolecular cross-couplingreactions that result in chain extension instead of cyclization alsoinevitably lead to linear impurities. As even trace non-cyclicimpurities can have pronounced effects on the physical properties of asample,^(13,14) exhaustive purification to remove linear by-products,¹⁵biphasic conditions,¹⁶ or preparatory-scale gel permeationchromatography (GPC) is often necessary.

Ring-expansion polymerization is another method for accessing cyclicpolymers.¹ The mechanism involves the insertion of a monomer into agrowing ring, such as at a metal-carbon or metal-oxygen bond. Thismethod does not suffer the same low-concentration limitations as ringclosure, which makes it an appealing approach for the synthesis ofcyclic polymers of high molecular mass.¹⁸ A dibutyltin catalystdeveloped by Hans and Kricheldorf⁹ was one of the first examples of thistype of polymerization. Although an effective example of the synthesisof macrocyclic polymers, the dibutyltin catalyst is limited to thepolymerization of lactones. More-recent catalysts^(18, 20-22) showpromising results, but again each catalyst is tuned to a specificmonomer. Ring-expansion olefin metathesis polymerization (REMP),introduced by Grubbs and co-workers,^(23, 24) is another approach toproducing cyclic polymers efficiently. Although the ring-expansionmethod of creating cyclic polymers is much preferred to thepost-polymerization processing required in ring closure for large-scalesynthesis, ring expansion is not without limitations. As an example, inREMP backbiting occurs as the degree of polymerization increases,²⁵ andtrace linear alkenes need to be removed from the monomer feedstock.²⁶

Additionally, REMP catalyst systems require a cyclic monomer, forexample, cyclooctene and its derivatives. It would be beneficial toemploy more readily available and cheaper substrates. Thus, alongstanding general challenge in polymer chemistry is to synthesizecyclic polymers efficiently, with diverse compositions, high purity,high molecular weights, and from readily available and inexpensivemonomers.

Conjugated macrocyclic polyenes are an area of considerable interest.Large conjugated macrocyclic materials can be useful in host-guestchemistry²⁷ and in the self-assembly of more-complicated one-, two- andthree-dimensional structures.²⁸ The ability of these macrocycles toself-assemble via TC-TC interactions can lead to a variety of unusualstructures, and thus physical properties.²⁹ A longstanding generalchallenge in both work that involves conjugated macrocycles and polymerchemistry is an efficient synthesis that allows for diversecompositions, ensures high purity and high molecular masses and can bemade from readily available and inexpensive monomers.³⁰

U.S. International Patent Application No. PCT/US2012/065841, filed Nov.19, 2012 discloses the preparation of tridentate pincer ligand supportedmetal complexes, which are either trianionic pincer ligand supportedmetal-alkylidyne complexes or tetra-anionic pincer ligand supportedmetallacycloalkylene complexes that are formed from trianionic pincerligand supported metal-alkylidyne complexes and alkynes. A trianionicpincer ligand supported metal-alkylidyne complex can be used as apolymerization precatalyst to polymerize an alkyne.

A trianionic pincer ligand supported metal-alkylidyne complex has thefollowing structure:

where: R is, independently, H, methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl t-butyl, or larger alkyl, or any other substituent thatdoes not inhibit formation of the metal-alkylidyne M-C triple bond ofthe trianionic pincer ligand supported metal-alkylidyne complex; R′ ismethyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, C5-C22alkyl, phenyl, naphthyl, or C₁₃-C₂₂ aryl; X, independently, can be O, N,S, P, or Se; R″, independently, is methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, t-butyl, C5-C₂₂, phenyl, naphthyl, C₁₃-C₂₂ aryl, ortwo R″ is a C₄-C6 alkylene combined with a single X as a heterocycle; nis 1 to 3 depending on X; m is 1 to 2; and M is a group 5-7 transitionmetal.

A tetra-anionic pincer-ligand supported metallacycloalkylene complex hasthe following structure:

where: R is, independently, H, methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, t-butyl, or larger alkyl, or any other substituentthat does not inhibit formation of the tetraanionic pincer-ligandsupported metallacycloalkylcne; R′ is, independently, methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, C₅-C₂₂ alkyl, phenyl,naphthyl, C₁₃-C₂₂ aryl, substituted aryl, or trimethylsilyl; R′″ is H ormethyl; X, independently, is O, N, S, P, or Se; R″, independently, canbe methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl t-butyl, C₅-C₂₂,phenyl, naphthyl, C₁₃-C₂₂ aryl, or two R″ are C₄-C₆ alkylene combinedwith a single X as a heterocycle; n is 1 to 3 depending on X; m is 1 to2; and M is a group 5-7 transition metal.

As shown in FIG. 1, complex 1 is a precatalyst and is converted intocomplexes 2 and 3, with complex 2 being the more-activealkyne-polymerization catalyst. In an original report,³² complex 2 isdemonstrated to be able to polymerize a wide variety of alkynes;however, the topology of the polymers is not addressed. In addition, thesynthesis of complex 2 proved inefficient, as the less active complex 3forms in a 33% yield. Another drawback in the original report is thatcomplexes 2 and 3 instantaneously react with any excess phenylacetylene,which consumes the catalyst, reduces the yield and requires anadditional purification step. The synthesis disclosed herein provides asolution to this catalyst-preparation problem in the original report.Treating complex 1 with excess 3,3-dimethyl-1-butyne, as opposed tophenylacetylene, complex 4, a catalyst, forms exclusively in aquantitative isolable yield (FIG. 1). As shown in FIG. 1, treatingcomplex 1 with phenylacetylene leads to complexes 2 and 3 in a 2:1 ratioand requires purification and separation procedures. Complex 3 exhibitsa low activity and is typically discarded, which thus educes the overallcatalyst yield. An improved synthesis involves treating complex 1 withtert-butylacetylene to provide catalyst 4 exclusively and in 100% yieldby simply evaporating to remove the solvent.

As shown in FIG. 1, the preparation of the tetra-anionic pincer-ligandsupported metallacycloalkylenc complex at low temperature with twoequivalents of an acetylene monomer gives a mixture of products towardpolymerization. In an embodiment of the invention, multiple equivalentsof the acetylene monomer is included with the trianionic pincer ligandsupported metal-alkylidyne complex at room temperature results in asingle tetra-anionic pincer-ligand supported metallacycloalkylenecomplex with two like monomers on the resulting tetra-anionicpincer-ligand supported metallacycloalkylene complex, as indicated inEquation 1, below.

A trianionic pincer ligand supported metal-alkylidyne complex or atetraanionic pincer ligand supported metallacyclopropene complex can beused as a polymerization catalyst for the polymerization of alkynesusing. The poly(alkyne)s prepared by this method can display one or moregeometries across the resulting double bonds of the poly(alkyne)backbone. The all cis alkylene chain, indicated by Equation 2, is forillustrative purposes only, and is not intended to suggest the geometryto be expected upon polymerization of all possible monomers, using allpossible trianionic pincer ligand supported metal-alkylidyne complexes,or under any set of reaction conditions. The polymerization reactionoccurs upon combining the trianionic pincer ligand supportedmetal-alkylidyne complex to an alkyne monomer, in a fluid state, whichcan be in solution. The alkyne can be unsubstituted, monosubstituted, ordisubstituted. The trianionic pincer ligand supported metal-alkylidynecomplex can be a neutral complex or an anion of a salt when employedwith a strong electrophile, such as methyl triflate. The polymerizationcan be carried out at relatively mild conditions, for example, ambienttemperatures at dry conditions under an inert atmosphere. Thepolymerization can occur with a large turnover of monomer per catalyst,a high degree of polymerization, and a high yield of polymer. As wouldbe expected by those skilled in the art, the rate of polymerization andthe practical conversion varies with the nature of the monomer, catalystand conditions for the polymerization. In an embodiment of theinvention, the resulting poly(alkyne) can be a cyclic polymer.

A combination of nuclear magnetic resonance (NMR) spectroscopy,combustion analysis and solid-state X-ray characterization served toidentify unambiguously the composition of complex 4. Three singlets inthe ¹H NMR spectrum (C₆D6) of complex 4 are attributable to thealkylidene ^(t)Bu, the pincer ^(t)Bu and the coordinated acetylene^(t)Bu groups in a 1:2:1 ratio at 0.90, 1.20 and 1.66 ppm, respectively.A singlet at 11.66 ppm corresponds to the terminal proton attached tothe q²-bound alkyne. In the 13C{¹H} NMR spectrum, the alkylidene carbonappears at 268.8 ppm, consistent with known pincer-supported alkylidenecomplexes.³³

FIG. 2 shows the molecular structure of complex 4 with ellipsoids drawnat the 50% probability level and disordered THF atoms and latticesolvent molecule (pentane) removed for clarity. FIG. 2 depicts theresults of a single-crystal X-ray diffraction experiment performed oncrystals that deposit with the slow evaporation of a concentratedsolution of complex 4 in pentane. The solid-state structure confirmsthat the alkylidyne present in complex 1 undergoes a formal reductivemigratory insertion into the W-arene bond of the pincer, a particularlyrare transformation. In the solid state, complex 4 is pseudo C_(s),symmetric and contains a W(IV) ion in a non-standard polyhedralgeometry. Complex 4 contains a tetraanionic pincer ligand that comprisestwo phenolates and an alkylidene connection. The phenolate O atoms spanthe trans positions with an O1-W1-O2 bond angle of 152.37(6)°. Thecoordinated THF experiences a strong trans influence from thetungstenalkylidene, evidenced by a long W1-O3 bond of 2.328(1) Å, and islabile. For comparison, the THF ligands in 1 are labile and also havelong W—O bonds (2.473(2) Å and 2.177(2) Å), with the longest being transto the alkylidyne. The C32-C27 distance (1.312(4) Å) is significantlyelongated from a typical C≡C bond length of 1.21 Å, and is betterrepresented as a double bond and thus the resonance form of ametallacyclopropene.

In the case of ring-expansion polymerization, it is common that evensmall changes to the metal complex can cause large differences inactivity.³¹ Fortunately, complex 4 maintains the remarkable highactivity observed for catalyst 2. Loading complexes 2 or 3, or the newcomplex 4, in a 10,000:1 phenylacetylene-lo-catalyst ratio in 2 ml oftoluene results in polymerization and a product we now understand to becyclic poly(phenylacetylene). In the first two minutes ofpolymerization, 2 averages 6.89×10⁶ g mol⁻¹ h⁻¹, 3 averages 4.39×10⁶ gmol⁻¹ h⁻¹, but incredibly 4 averages 9.00×10⁶ g mol⁻¹ h⁻¹. Not only doescomplex 4 have excellent activity, it achieves complete conversion underthese conditions with a turnover number of ˜10,000 after 22 minutes.This remarkable activity is maintained on scale up; submitting complex 4to 2 ml of phenylacetylene in 20 ml of toluene in a monomer-to-catalystratio of 5,000:1 and in one of 10,000:1 results in 96% (1.79 g) and 83%(1.54 g), respectively. The catalyst is tolerant to a variety offunctionalized acetylenes, such as ethers, halides and disubstitutedacetylenes, although all have effects on the polymerization activity andmolecular masses. Achievable molecular masses for phenylacetylene rangedfrom 8,000 to 130,000 Da.

The polymerization carried out in the presence of styrene or excessTEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy), a radical trap, does notalter or inhibit the polymerization of phenylacetylene, which rules outa radical mechanism.

Several common methods exist that provide compelling supportive evidencefor a cyclic topology when compared with an identical linear analogue.Cyclic polymers have a smaller hydrodynamic volume and thus longerelution time by GPC compared with the linear analogues. Also, static anddynamic light-scattering (SLS and DLS, respectively) techniques canconfirm that cyclic polymers have smaller particle radii than those ofthe linear equivalents. Calculations indicate the root mean square(r.m.s.) radius of gyration (

R_(g) ²

^(0.5)) of a cyclic polymer is half that of the same polymer in a lineartopology.³⁵ In some cases, it is possible to open the resultingmacrocycle through bond cleavage, which results in a linear topology anda subsequent change in physical properties.²³ Linearpoly(phenylacetylene) synthesized using (acetylacetonato)(1,5-cyclooctadiene)rhodium(1) (acac(Rh(1)cod))^(36,37) as a catalystprovides a comparison with the cyclic polymers produced by complex 4,and by matching molecular masses and polydispersities (PDIs), any changein physical properties observed is evidence for a difference intopology. Using DLS and SLS techniques, the hydrodynamic radius (R_(H))and r.m.s. radius of gyration (

R_(g) ²

^(0.5)) were determined for the linear and cyclic polymers. It is wellunderstood that the ratio of R_(Hcyclic)/R_(Hlinear)=0.9³⁸ and

R_(g) ²

cyclic/

R_(g) ²

_(linear)=0.5.³⁵

Table 1 lists the experimental values of R_(H) and R_(g) for the cyclicand linear polymers. With little doubt, the experimentally determinedratios clearly support that the polymers produced with catalyst 4 arecyclic. The experimental ratios of R_(Hcyclic)/R_(Hlinear)=0.86(7) and

R_(g) ²

_(cyclic)/

R_(g) ²

_(linear)=0.53(6) clearly indicate a close fit with the relationshipbetween a cyclic and a linear sample. Although comparing radii at asingle molecular mass is useful, it is important to ensure that thedifference is the same over a wide range of molecular masses.

TABLE 1 M_(nt) M_(w)/M_(n) and R_(H) values for molecular-mass matchedlinear and cyclic poly(phenylacetylene) Sample M_(n) (absolute) (Da)M_(w)/M_(n) Radius (R_(H))* (nm) Cyclic^(†) 45,600 1.95 2.21(17)Linear^(‡) 47,300 2.22 2.58(2)  *Hydrodynamic radius as measured intoluene at room temperature. ^(†)Sample was prepared by the addition ofphenylfacetylene to a solution of complex 4 in toluene and quenchedafter five minutes. ^(‡)Sample was prepared by the addition ofphenylacetylene to a solution of acac(Rh(1)cod) in THF and quenchedafter three hours.³⁷

Cyclic poly(phenylacetylene), an unprecedented cyclic polymer, is nowaccessible in high yield from the polymerization of inexpensivephenylacetylene. By treating the alkylidyne complex 1 with3,3-dimethyl-1-butyne rather than phenylacetylene, the active alkynepolymerization complex 4 forms in quantitative isolable yield. Theimproved catalyst preparation is beneficial, and equally important isthat complex 4 retains a high activity for the ring-expansionpolymerization of phenylacetylene. A combined multiexperiment approachprovides unambiguous evidence of a cyclic topology as compared withauthentic linear samples. DLS and SLS techniques provide (Rg²) and RHratios of cyclic versus linear samples that clearly indicate adifference in topology. Complementing the light-scattering data,intrinsic viscosities ((17)) measured over a wide range of molecularmasses clearly demonstrate the topological relationship betweenauthentic linear samples and cyclic samples produced by catalyst 4. Ringopening of partially hydrogenated samples of cyclicpoly(phenylacetylene) leads to polymers that exhibit larger hydrodynamicvolumes, as determined by GPC. Hydrogenating cyclicpoly(phenylacetylene) provides cyclic polystyrene that exhibits GPCelution times significantly longer than those of authentic samples oflinear poly(styrene) with similar absolute molecular masses. Complex 4,which features the unique tetraanionic pincer ligand, now enables accessto a new class of polymers from commercially available alkynes, and thehigh activity (9.0×10⁶ g mol⁻¹ h⁻¹) will permit access to largequantities of high-purity conjugated cyclic polymers.

According to the disclosed embodiments, once cyclic polymers aresynthesized by employing a tungsten catalyst that efficientlypolymerizes common alkynes to form macrocyclic polyenes, unsaturatedmacrocyclic polyenes can be further hydrogenated to form saturatedcyclic polymers. In particular, the disclosed embodiments providebranched cyclic polyolefins synthesized via the use of complex 4 as acatalyst.

FIG. 3 illustrates a scheme for synthesis of a saturated cyclic polymerhaving the following formula:

In formula (I), n varies widely across the different polymers andconditions. The size of the polymer can vary. In some embodiments, n isan integer equal to 2, 4, 7 and 12, and p is any integer greater than orequal to 1, such as 1, 2, 3, etc. According to the disclosedembodiments, long-chained terminal alkynes can be polymerized to producea polymer. The polymer can be further hydrogenated to produce a“polyolefin” that resembles cyclic low density polyethylene.Alternatively, acetylene and a long-chained alkyne can be copolymerizedto introduce “polyethylene” spacer groups between the chains oncehydrogenated.

In particular, a saturated cyclic polymer can be produced byhydrogenating an unsaturated cyclic polymer with a hydrogenationcatalyst such as palladium on carbon (Pd/C). The unsaturated cyclicpolymer can be produced by mixing alkyne monomers with a catalyst or aprecatalyst, thereby allowing the alkyne monomers to incorporate into anunsaturated cyclic polymer. The catalyst or precatalyst can be selectedfrom a group consisting of a trianionic pincer ligand supportedmetalalkylidyne complex, a tetra-anionic pincer-ligand supportedmetal-alkyne, and a tetra-anionic pincer-ligand supportedmetallacycloalkylene complex.

In an embodiment, an alkyne monomer selected from a group consisting of1-hexyne, 1-octyne, 1-nonyne, and 1-pentadecyne is used to synthesize asaturated cyclic homopolymer. FIG. 4 shows a scheme for synthesis of thesaturated cyclic homopolymer of 1-hexyne, 1-octyne, 1-nonyne, or1-pentadecyne, according to an embodiment of the disclosed invention. Asshown in FIG. 4, a saturated cyclic homopolymer is produced byhydrogenating an unsaturated cyclic polymer with a hydrogenationcatalyst. The hydrogenation catalyst can be palladium on carbon (Pd/C),Crabtree's catalyst ([Ir(COD)(py)(PCy₃)]⁺[PF₆]⁻, whereCOD=cyclooctatetraene, py=pyridine, and Cy=cyclohexane), etc. Theunsaturated cyclic polymer can be produced by mixing a single type ofalkyne monomers with a catalyst (complex 4), thereby allowing the singletype of alkyne monomers to form into an unsaturated cyclic homopolymer,which has the following structural formula:

wherein: R is n-butyl, n-hexyl, n-heptyl, or n-tetradecyl; n varieswidely across the different polymers and conditions and can be a valueof 1 or more than 1.

Upon hydrogenation of the unsaturated cyclic polymer (formula II), asaturated cyclic homopolymer is produced. The saturated cyclichomopolymer has the following structural formula:

wherein: R is n-butyl, n-hexyl, n-heptyl, or n-tetradecyl; n varieswidely across the different polymers and conditions and can be a valueof 1 or more than 1. The saturated cyclic homopolymer incorporates asingly type of monomers selected from the group consisting of 1-hexyne,1-octyne, 1-nonyne, and 1-pentadecyne. In an embodiment, the saturatedcyclic homopolymer is further purified. A relative purity of thesaturated cyclic homopolymer determined by a nuclear magnetic resonancespectroscopy (NMR) analysis can be about 75% to about 95%. In oneembodiment, a relative purity determined by an NMR analysis can be morethan about 95%. In an alternative embodiment, a relative puritydetermined by an NMR analysis can be 99%.

In an embodiment, a saturated cyclic copolymer is provided. Thesaturated cyclic copolymer is synthesized using acetylene and a secondalkyne monomer as comonomers. FIG. 5 shows a scheme for synthesis ofsaturated cyclic copolymers using acetylene and a second alkyne monomer,according to an embodiment of the disclosed invention. The second alkynemonomer is selected from the group consisting of 1-hexyne, 1-octyne,1-nonyne, and 1-pentadecyne. As shown in FIG. 5, a saturated cycliccopolymer can be produced by hydrogenating an unsaturated cycliccopolymer with a hydrogenation catalyst such as palladium on carbon(Pd/C). The unsaturated cyclic polymer can be produced by mixingacetylene and a second alkyne monomer, such as 1-hexyne, 1-octyne,1-nonyne, or 1-pentadecyne, with a catalyst, thereby allowing theacetylene and the second alkyne to incorporate into an unsaturatedcyclic copolymer, which has the following structural formula:

In structural formula (IV), R can be n-butyl, n-hexyl, n-heptyl, orn-tetradecyl. The values for “n” and “m” are varied and the ratio of n/mcan be a number varied from 0 to 1. In some embodiments, n is an integergreater than or equal to 1 and m is an integer greater than or equal to1.

Hydrogenation of the unsaturated cyclic copolymer results in a saturatedcyclic copolymer, which has the following structural formula:

In structural formula (V), “R” can be n-butyl, n-hexyl, n-heptyl, orn-tetradecyl. The values for “n” and “m” are varied. The ratio of n/mcan be a number varied from 0 to 1. In some embodiments, n is an integergreater than or equal to 1 and m is an integer greater than or equalto 1. The size of the polymer can vary.

Acetylene and the second alkyne monomer can be randomly incorporated inthe saturated cyclic copolymer at a variable ratio. As a result, a ratioof comonomer incorporation, which is incorporated acetylene/incorporatedsecond alkyne monomer, in the saturated cyclic copolymer varies. Forexample, in an alternative embodiment, in a saturated cyclic copolymerwhere R is hexyl, a ratio of incorporated acetylene to incorporatedsecond alkyne monomer is about 59:41, 47:53, or 34:66. It should beappreciated that where R is hexyl, the ratio of incorporated acetyleneto incorporated second alkyne monomer has the incorporated acetylenebetween 34 and 59 and the second alkyne monomer between 41 and 66. Inanother alternative embodiment, in a saturated cyclic copolymer where Ris tetradecane, a ratio of incorporated acetylene to incorporated secondalkyne monomer is about 15:85. In an alternative embodiment, in asaturated cyclic copolymer where R is heptyl, a ratio of incorporatedacetylene to incorporated second alkyne monomer is about 43:57 or about15:85. It should be appreciated that where R is heptyl, and a ratio ofincorporated acetylene to incorporated second alkyne monomer has theincorporated acetylene between 15 and 43 and the second alkyne monomerbetween 57 and 85.

The saturated cyclic copolymer can be further purified. In anembodiment, a relative purity of the saturated cyclic copolymerdetermined by a nuclear magnetic resonance spectroscopy (NMR) analysisis about 75% to about 95%. In one embodiment, a relative puritydetermined by an NMR analysis can be more than about 95%. In analternative embodiment, a relative purity determined by an NMR analysiscan be 99%.

These disclosed saturated cyclic polymers have different and potentiallyinteresting rheological and viscometric properties. They can be usefulas additives to known polyolefins.

The disclosed invention is further defined in the following Examples. Itshould be understood that these Examples are given by way ofillustration only. From the above discussion and these Examples, oneskilled in the art can ascertain the essential characteristics ofembodiments of the disclosed invention. Without departing from thespirit and scope thereof, one skilled in the art can make variouschanges and modifications of the invention to adapt it to various usagesand conditions. All publications, including patents and non-patentliterature, referred to in this specification are expressly incorporatedby reference herein.

EXAMPLES Example 1

Methods

Synthesis of complex 4 ([^(t)BuOCHO]W≡C(CH₃)3(O^(t)Bu)(THF))

In a nitrogen filled glovebox, a glass vial equipped with a stir bar wascharged with 1 (400 mg, 0.52 mmol) and dissolved in toluene (5.0 mL).3,3-dimethyl-1-butyne (214 mg, 321 μL, 2.60 mmol) was added viamicropipette with stirring. After 5 min, the solvent and residual3,3-dimethyl-1-butyne were removed in vacuo to yield the light brownsolid complex 4 in >99% yield (405 mg, 0.52 mmol), for the reactionindicated in Equation 2, above. The resulting solid was dissolved inminimal pentane and cooled to −35° C. to yield single crystals 10amenable to X-ray diffraction, where the molecular structure is shown inFIG. 2. ¹H NMR (500 MHz, C₇D8, δ (ppm)): 11.61 (s, 1H, W—CH₃₂), 7.41 (d,2H, Ar—H_(8,10)), 7.28 (dd, 2H, ArH_(3,16)), 7.26 (t, 1H, Ar—H₉), 7.19(dd, 2H, Ar—H_(5,14)), 6.77 (t, 2H, Ar—H_(4,15)), 3.60 (t, 4H,THF—H_(38,41)), 1.66 (s, 9H, W—C—C(CH₃)₃(H₂₉₋₃₁)), 1.20 (s, 18H, ligandC(CH₃)₃(H_(20-22,24-26))), 1.16 (t, 4H, THF—H_(39,40)), 0.90 (s, 9H,W═C(CH₃)₃(H₃₅₋₃₇)). ¹³C NMR: 268.8 (s, W═CC(CH₃)₃ (C₃₃)), 213.0 (s,WCCC(CH₃)₃(C₂₇)), 184.0 (s, WCCC(CH₃)₃(C₃₂)), 168.5 (s, C_(1,18)), 153.7(s, Ar—C_(7,11)), 137.4 (s, Ar—C_(6,13)), 137.3 (s, Ar—C_(2,17)), 132.5(s, Ar—C₁₂), 130.9 (s, Ar—C₉), 129.2 (s, Ar—C_(8,10)), 128.2 (s,Ar—C_(3,16)), 125.7 (s, Ar—C_(5,14)), 118.7 (s, Ar—C_(4,15)), 71.3 (s,THF—C_(38,41)), 46.0 (s, W═CC(CH₃)₃(C₃₄)), 39.2 (s, WCCC(CH₃)₃(C₂₈)),36.0 (s, W═CC(CH₃)₃(C₃₅₋₃₇)), 34.3 (s, ligand C(CH₃)₃(C_(19,23))), 31.1(s, WCCC(CH₃)₃(C₂₉₋₃₁)), 30.1 (s, ligand C(CH₃)₃(_(C20-22,24-26))),25.00 (s, THF C_(39,40)). Anal. Calcd.: C: 63.24% H: 6.99%, Found: C:63.28%, H: 7.09%.

General Polymerization Procedure

In an inert atmosphere glovebox, toluene (2.0 ml) was added to a glassvial equipped with a stir bar. Phenylacetylene (218 μl, 2.00 mmol) wasadded via a micropipette with stirring. A stock solution (1 mg ml⁻¹) of4 (157 μl, 0.20 μmol) was added to the stirring solution in one shot toinitiate the polymerization. Polymerization was terminated via theaddition into tenfold excess of stirring diethyl ether. The resultingpolymer samples were isolated via vacuum filtration and the residualsolvent was removed in vacuo.

General Procedure for Hydrogenation

In an argon or nitrogen filled glove-box, the polymer to be hydrogenatedis dissolved in toluene upon stirring at room temperature for fewminutes. To this solution, 100 wt % of Pd/C is added, and the glass vialcontaining the reaction mixture is capped with a septum. A needle isstick to the septum allowing for atmosphere exchange between theinterior of the vial and the exterior, but avoiding solvent spill duringhydrogenation. The vial glass is placed inside of a Parr bomb, which issealed and loaded with H2 up to 800 psi (after flushing H2 twice beforeachieving the desired pressure). The reaction system is heated up to 90°C. and allowed to stir for 7 days. The pressure is released and thesolutions of hydrogenated polymers are filtered through celite, followedby solvent removal under reduced pressure. Samples were dried overnightunder vacuum.

Example 2

Cyclic Polyolefins

Cyclic polymers are known to have significantly different propertiesfrom their linear analogues. While a lot of attention has turned tothese polymers and their properties, their synthesis in large scalestill demonstrates a challenge and limits their applications.

In 2013, the Veige group developed the most active catalyst for alkynepolymerization, and its proposed mechanism indicated a cyclic topologyfor the resulting polymers.³² A recent work published by Veige et al.³¹introduced a variation of this catalyst, which stands right behind it asthe second most active alkyne polymerization catalyst, but with a muchmore advantageous and economic synthesis. This work also confirmed theassignment of the generated polymers as cyclic by comparing propertiessuch as hydrodynamic volume, viscosity and radius of gyration, withtheir linear counterparts.

Low density polyethylene (LDPE) is among the most used polymers, findingapplications that range from plastic bags and packaging to tubing andelectrical cables, reaching a worldwide market of about US$33 billion in2013. LDPE and high density polyethylene (HDPE) show very differentproperties, for instance LDPE has less hardness and strength than HDPE,but it is more ductile. These differences lead to distinct properties,employed in various industry fields. An important point to behighlighted is that both commercial LDPE and HDPE are linear. The ideaof being able to synthesize cyclic LDPE in larger scale and evaluate thenew properties that can rise from this polymer is very attractive.

General Considerations

Toluene used was dried using a GlassContour drying column. 1H and 13CNMR spectra were obtained on Varian INOVA spectrometer, operating at 500MHz for proton. Chemical shifts, reported in δ (ppm), were referenced onthe solvent, on the TMS scale for 1H and 13C. Monomers 1-nonyne,1-pentadecyne, 1-hexyne and 1-octyne were dried over 4 Å molecularsieves, submitted to 3-cycles of freeze-pump-thaw, and brought to aglove-box of either nitrogen or argon atmosphere. Acetylene gas waspurchased from Air Gas, and purified by passing through a trap ofchloroform and liquid nitrogen.

General Procedure for the Synthesis of Homopolymers

In this example, homopolymers are synthesized using the linear alkynes(1-hexyne, 1-octyne, 1-nonyne, 1-pentadecyne).

In a nitrogen or argon filled glove box, the desired monomer isdissolved in toluene in a 50 mL round bottom flask equipped with astirring bar. A solution of catalyst in toluene is prepared and added atone shot to the monomer solution, with the volume varying according tothe number of equivalents necessary. Instantaneous color change andincrease in viscosity is observed for all polymerizations. Afterstirring for certain periods of time, the polymers are brought out ofthe glove-box and added to stirring methanol. The precipitated polymersare isolated by filtration and dried under vacuum overnight.

Exemplary results for the synthesis of homopolymers are summarized onTable 2. As shown in Table 2, the homopolymerization of all the linearalkynes provided good to very good yields of polymer when using 1:5000monomer to catalyst ratio. The polymerization was conducted in tolueneat room temperature. When a toluene solution of the catalyst was addedto a toluene solution of the monomer the transparent solution turnsinstantaneously to bright orange. A change in viscosity was alsoobserved. The polymers were precipitated by slow addition to stirringmethanol. All of the homopolymer synthesized are orange tacky solids.

TABLE 2 Exemplary conditions for the synthesis of homopolymers 1-hexyne,1-octyne, 1-nonyne, and 1-pentadecyne. Monomer/ Mass of Total ReactionBatch Catalyst Monomer Volume Time Yield Polymer Monomer Name ratio (g)(mL) (min) (%) Color 1-hexyne Hex-1 5000:1 2.0 30 5 94 orange 1-octyneOct-1 5000:1 2.0 15 5 80 orange 1-nonyne Non-1 5000:1 2.0 50 5 94 orange1-pentadecyne Ptd-1 5000:1 2.0 50 5 83 orangeGeneral Procedure for the Synthesis of Copolymers

In a nitrogen or argon filled glove box, the desired monomer isdissolved in toluene in a 50 mL round bottom flask equipped with astirring bar. The reaction flask is sealed using a rubber septum andtaken outside of the glove-box. A toluene solution of catalyst isprepared inside the glove-box, transferred to a gas-tight Hamiltonsyringe, and brought outside along with the reaction flask. Acetylene isbubbled through the solution of the monomer for 3 minutes. After thisperiod, the flow of acetylene is suspended but a balloon filled withthis gas remains connected to the system to provide further acetylene ifnecessary. The toluene solution of the catalyst is then added in oneshot via syringe to the monomer solution, with the volume varyingaccording to the number of equivalents necessary. The ratio of monomerto catalyst is based on the amount of the monomers other than acetylene.Instantaneous color change and increase in viscosity is observed for allpolymerizations. After stirring for certain periods of time, thepolymers are added to stirring degassed methanol, under argon flow. Theprecipitated polymers are isolated by filtration, dried under vacuumovernight, and stored under inert atmosphere.

The copolymers are in general slightly soluble in toluene. A drop in theyield of the copolymers is observed when compared to homopolymers. Thelower yields may be due to the low solubility of chains that would bemainly composed of acetylene. Such polymer chains containing the activecatalyst would precipitate before incorporating any of the long-chainedmonomer. In some cases, a larger amount of solvent is used and theresulting copolymers appear to have a higher incorporation of acetyleneaccompanied by a drop in yield. For copolymers synthesized usingidentical procedures, some differences are observed, such as yield andacetylene incorporation. The results again indicate that copolymers withhigher acetylene incorporation are obtained in lower yields. The resultsrelated to the copolymers synthesized are summarized in Table 3.

TABLE 3 Exemplary conditions for the synthesis of copolymers ofacetylene with one of the following: 1-hexyne, 1-octyne, 1-nonyne, and1-pentadecyne. Monomer/ Mass of Total Reaction Batch Catalyst MonomerVolume Time Yield Polymer Monomer Name ratio (g) (mL) (min) (%) ColorAcetylene/1- Ac-Hex-1 5000:1 1 10 5 20 purple hexyne Acetylene/1-Ac-oct-1 10000:1  4 80 10 25 Dark purple octyne Acetylene/1- Ac-Non-15000:1 2.0 10 10 40 dark red nonyne Acetylene/1- Ac-Non-2 5000:1 2.0 1010 20 dark red nonyne Acetylene/1- Ac-Non-3 5000:1 2.0 10 10 62 dark rednonyne Acetylene/1- Ac-Ptd-1 1000:1 1.0 5 5 99 redish brown pentadecyneAcetylene/1- Ac-Ptd-2 5000:1 1.0 10 10 17 dark purple pentadecyne

The incorporation of the long-chained alkyne into the acetylene can beestimated by integrating the ¹H NMR olefinic and aliphatic region. Table4 illustrates an exemplary incorporation in percentages for all thesynthesized copolymers.

TABLE 4 Exemplary incorporation of Long-chain Alkyne into polyacetylene.Polymer Long-Chain Alkyne Incorporation percentage Ac-Non-1 >99% Ac-Non-2 57% Ac-Non-3 85% Ac-Ptd-1 84% Ac-Ptd-2 85% Ac-oct-1 41%Ac-hex-1 >99% General Procedure for Hydrogenation

In an argon or nitrogen filled glove-box, the polymer to be hydrogenatedis dissolved in toluene upon stirring at room temperature for fewminutes. To this solution, 100 wt % of Pd/C is added, and the glass vialcontaining the reaction mixture is capped with a septum. A needle isstick to the septum allowing for atmosphere exchange between theinterior of the vial and the exterior, but avoiding solvent spill duringhydrogenation. The vial glass is placed inside of a Parr reactor, whichis sealed and loaded with H2 up to 800 psi (after flushing H2 twicebefore achieving the desired pressure). The reaction system is heated upto 90° C. and allowed to stir for 7 days. The pressure is released andthe solutions of hydrogenated polymers are filtered through celite,followed by solvent removal under reduced pressure. Samples are driedovernight under vacuum.

Exemplary hydrogenation conditions are shown in following Table 5 andTable 6. Table 5 summarizes the exemplary results obtained for thehydrogenations of the synthesized homopolymers. Table 6 summarizes theexemplary results obtained for the hydrogenations of the synthesizedcopolymers.

TABLE 5 Exemplary reaction conditions for hydrogenations of Hex-1,Oct-1, Non-1 and Ptd-1. Mass of Batch Catalyst Temperature Pressure TimePolymer Yield Polymer Polymer Name Loading (° C.) (psi) (days) (g) (%)Color Hex-1 Hex-H-1 100 wt % 90 1000 7 0.500 99 clear Oct-1 Oct-1-H 100wt % 90 1000 7 0.422 60 Light orange Non-1 Non-1-H 100 wt % 90 1000 70.984 67 Light yellow Ptd-1 Ptd-1-H 100 wt % 90 1000 7 0.869 74 Lightyellow

TABLE 6 Exemplary reaction conditions for hydrogenations of Ac-Hex-1,Ac-Oct-1, Ac-Non-1, Ac-Non-3 and Ac-Ptd-1. Mass of Batch CatalystTemperature Pressure Time Polymer Yield Polymer Polymer Name Loading (°C.) (psi) (days) (g) (%) Color Ac-Hex-1 Ac-Hex-H-1 100 wt % 90 1000 70.168 25 Light yellow Ac-Non-1 Ac-Non-H-1 100 wt % 90 1000 7 0.700 59Light yellow Ac-Non-3 Ac-Non-H-2 100 wt % 90 1000 7 0.680 79 Lightyellow Ac-Ptd-1 Ac-Ptd-H-1 100 wt % 90 1000 7 0.684 50 Light yellow

The non-hydrogenated copolymers decompose in air. Special care has beentaken to store all the polymers under an inert atmosphere, usingdegassed solvent for quenching and limiting their exposure to oxygen.

NMR Spectroscopic Data for Hydrogenated Polymers

NMR spectra were obtained on Varian INOVA 500 MHZ and Varian INOVA2 500MHz spectrometers. Chemical shifts are reported in δ (ppm). For ¹H and¹³C NMR spectra, the residual solvent peaks were used as an internalreference standard. Samples were prepared by placing solid polymer andan appropriate amount of a deuterated solvent into an NMR tube.Exemplary NMR spectroscopic data for hydrogenated homopolymerPoly(1-Hexyne) is illustrated in FIG. 6. FIG. 6 shows ¹H NMR spectrumfor of Hex-1-H in CDCl₃ at 25° C., according to an embodiment of thedisclosed invention.

Exemplary NMR spectroscopic data for hydrogenated homopolymerPoly(1-octyne) is illustrated in FIG. 7. FIG. 7 shows ¹H NMR spectrum ofpoly oct-1 in C6D6 at 25° C., according to an embodiment of thedisclosed invention.

Exemplary NMR spectroscopic data for hydrogenated homopolymerPoly(1-nonyne) is illustrated in FIG. 8. FIG. 8 shows ¹H NMR spectrum ofnon-1 (bottom) and non-1-H (top) in CDCl₃ at 25° C., according to anembodiment of the disclosed invention.

Exemplary NMR spectroscopic data for hydrogenated homopolymerPoly(1-pentadecyne) is illustrated in FIG. 9. FIG. 9 shows ¹H NMRspectrum of Ptd-1 (bottom) and Ptd-1-H (top) in CDCl₃ at 25° C.,according to an embodiment of the disclosed invention.

Exemplary NMR spectroscopic data for hydrogenated copolymerAcetylene/1-hexyne is illustrated in FIG. 10. FIG. 10 shows ¹H NMRspectrum of Ac-Hex-H-1 in CDCl₃ at 25° C., according to an embodiment ofthe disclosed invention.

Exemplary NMR spectroscopic data for hydrogenated copolymerAcetylene/1-nonyne is illustrated in FIG. 11 and FIG. 12. FIG. 11 shows¹H NMR spectrum of Ac-Non-H-1 in CDCl3 at 25° C., according to anembodiment of the disclosed invention. FIG. 12 shows ¹H NMR spectrum ofAc-Non-H-2 in C6D6 at 25° C., according to an embodiment of thedisclosed invention

Exemplary NMR spectroscopic data for hydrogenated copolymerAcetylene/1-pentadecyne is illustrated in FIG. 13. FIG. 13 shows ¹H NMRspectrum of Ac-Ptd-H-1 in CDCl3 at 25° C., according to an embodiment ofthe disclosed invention.

FIG. 14 is a picture of exemplary saturated cyclic polymers.

Hydrogenation Using Crabtree's Catalyst

Crabtree's catalyst ([Ir(COD)(py)(PCy₃)]⁺[PF₆]⁻, whereCOD=cyclooctatetraene, py=pyridine, and Cy=cyclohexane) is tested forhydrogenation of homopolymer (poly(1-pentadecyne). In an argon ornitrogen filled glove-box, the polymer to be hydrogenated is dissolvedin dichloromethane (DCM) upon stirring at room temperature for fewminutes. The round bottom flask containing the polymer is capped with arubber septum and brought out of the glovebox. 1 wt % of Crabtree'scatalyst ([Ir(COD)(py)(PCy3)]⁺[PF6]⁻) is dissolved in 1 mL of DCM, andbrought out of the glovebox using a gas-tight Hamilton syringe. Aftersaturating the polymer solution with H₂ the catalyst is added to it inone shot. The reaction mixture is stirred for three days with a balloonof H₂ attached to it and replaced when necessary. Thepoly(1-pentadecyne) changes from orange to light yellow. Filtering thereaction mixture through silica to remove the catalyst and evaporatingthe remaining solvent yields the hydrogenated homopolymer.Unfortunately, the same procedure fails to hydrogenate copolymers.

CONCLUSIONS

This example shows employing complex 4 to synthesize homopolymers of1-hexyne, 1-octyne, 1-nonyne and 1-pentadecyne, and also theircopolymers with acetylene. Hydrogenation of these copolymers utilizingPd/C yielded branched cyclic polyethylenes. The high pressurehydrogenation using Pd/C as a catalyst is for now the most effectivemethod for the hydrogenation of these copolymers. Alternatively, the useof Crabtree catalyst in a small amount, under 1 atm of H₂ at roomtemperature is a preferable method for the hydrogenation of homopolymersbut is still not suitable for copolymers.

Having described the many embodiments of the disclosed invention indetail, it will be apparent that modifications and variations arepossible without departing from the scope of the invention defined inthe appended claims. Furthermore, it should be appreciated that allexamples in the present disclosure, while illustrating many embodimentsof the invention, are provided as non-limiting examples and are,therefore, not to be taken as limiting the various aspects soillustrated.

It is intended that the invention not be limited to the particularembodiment disclosed herein contemplated for carrying out thisinvention, but that the invention will include all embodiments fallingwithin the scope of the claims.

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All documents, including any priority documents, patents, journalarticles and other materials cited in the present application areincorporated herein by reference.

While the disclosed invention has been disclosed with references tocertain embodiments, numerous modification, alterations, and changes tothe described embodiments are possible without departing from the sphereand scope of the disclosed invention, as defined in the appended claims.Accordingly, it is intended that the disclosed invention not be limitedto the described embodiments, but that it has the full scope defined bythe language of the following claims, and equivalents thereof.

What is claimed is:
 1. A composition comprising a saturated cycliccopolymer comprising a hydrogenated copolymer comprising randomlydispersed acetylene and a second alkyne monomer, said monomer selectedfrom group consisting of 1-octyne and 1-nonyne, and said saturatedcyclic copolymer having a structural formula:

wherein: R is n-hexyl, or n-heptyl; when R is n-hexyl, a molar ratio ofincorporated acetylene to incorporated second alkyne monomer is from 34to 59:41 to 66; when R is n-heptyl, a molar ratio of incorporatedacetylene to incorporated second alkyne monomer is from 15 to 43:57 to85; n is an integer greater than or equal to 1; and m is an integergreater than or equal to
 1. 2. A composition comprising a saturatedcyclic copolymer comprising a hydrogenated copolymer comprising randomlydispersed acetylene and a second alkyne monomer, and said saturatedcyclic copolymer having a structural formula:

Wherein: R is n-tetradecyl; a molar ratio of incorporated acetylene toincorporated second alkyne monomer is about 15:85; n is an integergreater than or equal to 1; and m is an integer greater than or equalto
 1. 3. The composition of claim 1, wherein R is hexyl, and a comonomermolar ratio of incorporated acetylene to incorporated second alkynemonomer is about 59:41.
 4. The composition of claim 1, wherein R ishexyl, and a comonomer molar ratio of incorporated acetylene toincorporated second alkyne monomer is about 47:53.
 5. The composition ofclaim 1, wherein R is hexyl, and a comonomer molar ratio of incorporatedacetylene to incorporated second alkyne monomer is about 34:66.
 6. Thecomposition of claim 1, wherein R is heptyl, and a comonomer molar ratioof incorporated acetylene to incorporated second alkyne monomer is about43:57.
 7. The composition of claim 1, wherein R is heptyl, and acomonomer molar ratio of incorporated acetylene to incorporated secondalkyne monomer is about 15:85.
 8. The composition of claim 1, wherein arelative purity of the saturated cyclic copolymer determined by anuclear magnetic resonance spectroscopy (NMR) analysis is about 75% toabout 99%.